def __init__(self, expression_in_infix_notation: str):
"""
:param expression_in_infix_notation: string with expression in infix notation
"""
self.expression_in_infix_notation = Queue_(expression_in_infix_notation)
self.expression_in_postfix_notation = ReversePolishNotation()
self.stack = Stack()
def __init__(self, expression_in_infix_notation: str):
self.expression_in_infix_notation = Queue_(expression_in_infix_notation)
self.expression_in_postfix_notation = ReversePolishNotation()
self.stack = Stack()
while not ReversePolishNotationConverter.is_open_bracket(self.stack.top()):
self.expression_in_postfix_notation.put(self.stack.top())
self.stack.pop()
self.stack.pop()
def __init__(self, infix_string: str):
self._infix_notation = Queue_(infix_string)
self._postfix_notation = ReversePolishNotation()
self.stack = Stack()
class ReversePolishNotationConverter:
def __init__(self, infix_string: str):
self._infix_notation = Queue_(infix_string)
self._postfix_notation = ReversePolishNotation()
self.stack = Stack()
point = '.'
def convert(self, expression_in_infix_notation: str) -> ReversePolishNotation:
while not self._infix_notation.empty():
character = self._infix_notation.get()
if self.is_part_of_digit(character):
digit = self.read_digit(character)
self._postfix_notation.put(digit)
continue
elif self.is_opening_bracket(character):
self.stack.push(character)
continue
elif self.is_closing_bracket(character):
self.pop_from_stack_until_opening_bracket()
continue
operator = OpFactory.get_op_by_symbol(character)
if self.is_binary_operation(operator):
self.pop_from_stack_until_prioritizing(operator)
else:
raise Exception(character)
while not self.stack.empty():
self._postfix_notation.put(self.stack.top())
self.stack.pop()
return self._postfix_notation
def pop_from_stack_until_opening_bracket(self):
while not self.is_opening_bracket(self.stack.top()):
self._postfix_notation.put_operator(self.stack.top())
self.stack.pop()
self.stack.pop()
def pop_from_stack_until_prioritizing(self, operator: Op, state: ReversePolishNotationConverterState):
current_priority = operator.priority
while not self.stack.empty() and self.stack.top().priority > current_priority:
self._postfix_notation.put(self.stack.top())
self.stack.pop()
self.stack.push(operator)
def read_digit(self, character: str) -> Digit:
digit = character
while not self._infix_notation.empty() and self.is_part_of_digit(self._infix_notation.top()):
digit += self._infix_notation.get()
return Digit(digit)
@staticmethod
def is_part_of_digit(character: str) -> bool:
return character.isdigit() or character == ReversePolishNotationConverter.point
@staticmethod
def is_open_bracket(character: str, operator: Op) -> bool:
if character == '(':
return True
return False
@staticmethod
def is_close_bracket(character: str, operator: Op) -> bool:
if character == ')':
return True
return False
@staticmethod
def is_binary_operation(operator: Op) -> bool:
return isinstance(operator, BinaryOp)